Powered boot lids allow a boot (also known as a “trunk”) of an automobile to be opened and closed without effort.
For example, in certain luxury automobiles, the hinges which attach the boot lid to the automobile are each driven directly by an electric motor with a downstream toothed gear mechanism see e.g. US2005/0150078.
This technique has certain disadvantages. Depending on the gearing, the directly driven mechanism can require a large motor for a heavy boot lid, or can operate very slowly.
Powered struts, which are generally simpler and cheaper than powered hinges, have been proposed for opening and closing tailgates, but these tend to be heavier and bulkier than the mechanism discussed above. For example, WO2009/03143 discloses a drive device for displacing a motor vehicle side door, hatch door (or “tailgate”) or trunk lid. Similarly, U.S. Pat. No. 8,403,397 discloses an adjustable tailgate support which preferably has an electric spindle drive. In WO2009/03143, a drive device is shown attached in the interior of the vehicle attached to one side of the vehicle, whereas in U.S. Pat. No. 8,403,397, supports are provided on both sides of the tailgate, and they are disposed in channels formed in the body between the interior and the exterior of the vehicle. Extension of these struts opens the tailgate/hatch door, which opens in an arc about the hinges, swinging outward then upward.
Certain disadvantages are associated with these arrangements, in which one part telescopes out of another in areas which are exposed to the environment. Specifically, dirt/dust/water can accumulate on the struts and can be detrimental to the operation of the struts, also dirty grease from struts can be transferred to items placed in the boot-space.
The struts are visible in use and can potentially obstruct attempts to put items inside the boot-space. Moreover the mechanism is exposed during opening/closing and therefore can be noisy.